ANCHORAGE, Alaska (Reuters) -- Anchorage residents could see a cloud of steam last weekend from a volcano 75 miles away -- one of three Alaska volcanoes showing signs of unrest.The three volcanoes, including two located on remote Aleutian islands distant from any population centers, are setting off frequent tremors and minor bursts of ash or steam, seismologists said on Tuesday.Cleveland Volcano, 900 miles southwest of Anchorage, had a small eruption on Friday, said the Alaska Volcano Observatory, which monitors Alaska's more than 40 active volcanoes.Its ash plume rose to a height of nearly 15,000 feet above sea level, observatory scientists said.A cloud of steam from the 11,070-foot Mount Spurr was visible from Anchorage during the weekend.The volcano has had periodic but minor ash emissions and some debris flow caused by melted snow, said Dave Schneider, a U.S. Geological Survey volcanologist and acting scientist-in-charge at the Alaska Volcano Observatory.Ash emissions "are a lot easier to see now than they were in the summer because you have fresh snow," Schneider said.Cleveland Volcano, which comprises the western half of uninhabited Chuginadak Island, last erupted in 2001. The closest community, 45 miles to the east, is Nikolski, an Aleut village of 36 people.The other volcano showing unrest is 5,925-foot Tanaga Volcano.A series of eruptions in 1992 showered Anchorage and the surrounding region with ash, forcing a brief closure of Anchorage International Airport.Copyright 2005 Reuters. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.